As interphones are becoming more widely used in all aspects, the functions that they can support are no longer limited to a call function. Instead, they are moving toward more intelligent functions that enable the radios to support more and more operation functions.
However, due to the limitation of the hardware conditions in the radios, for example, the limitation of the screen size, the implementation of all the operation functions in the radios is more difficult and has the defect of low efficiency.
For example, when an operation of sending a short message or editing contacts is necessary, since a Sudoku input method is usually used at present, it is complicated and cumbersome to switch numbers and characters, and switch capital and small letters in a two-way radio with a smaller screen size.